How to filter the type of e-mail addresses that can register?

Question

I want to be able to make my service only accessable by students, or someone with a .edu e-mail. What would be the best approach?

Answer 1

Probably, you need to make filter module(filter_email() funtion) to check registered e-mail. 

Comments

Right, so I would do something like this:
filter_email() {
if !(string.contains(.edu)) {
   invalid_email error;
}
}

Though where would I do that? Like I am not even sure where the e-mail is having it's standards set (if it is). For example: your e-mail won't proceed, unless you have a .